Dissipative Quantum Systems and Flow Equations

This work investigates dissipative quantum systems by means of Flow Equations for Hamiltonians. We start with the Spin-Boson Model including one bosonic mode. The Flow Equation results for the ground-state energy and for the transformation of the Pauli spin matrices are compared with the numerically exact solution. For the Spin-Boson Model with an arbitrary number of bosonic modes and explicitly broken reflection symmetry, general Flow Equations are set up using a truncation scheme which involves an l-dependent normal ordering procedure. Furthermore, observations on universal asymptotic behaviour are discussed. The remaining chapter investigates quantum Brownian motion in a periodic potential with broken reflection symmetry - employing the previous procedures. In this context we also include results for the Tomonaga-Luttinger Model with impurity.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Heidelberg

Year

2002

Author dc:creator

• Stauber, Tobias

Contributors dc:contributor

• Mielke, Andreas

Repository record source_url

http://www.ub.uni-heidelberg.de/archiv/1934

OAI identifier oai:identifier

oai:archiv.ub.uni-heidelberg.de:1934